Hydrostatic torque converter and torque amplifier

ABSTRACT

An example includes a hydraulically controllable coupling to couple a rotating input and to an output to rotate, or to decouple the input and the output, with coupling and decoupling modes selected by switching a hydraulic device such as a vane pump between a pumping mode and a mode in which it does not pump. In an example, the system cooperates with a transmission to increase the number of possible gear ratios in some examples.

PRIORITY CLAIMS AND RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 15/835,058, filed Dec. 7, 2017, which application is a continuationapplication of U.S. application Ser. No. 14/599,746, filed Jan. 19,2015, which is a continuation application of U.S. application Ser. No.13/510,643, filed May 18, 2012, which is a U.S. national stageapplication under 35 U.S.C. § 371 of PCT/IB2010/003161, filed Nov. 19,2010, and published as WO 2011/061630 A2 on May 26, 2011, which claimspriority to U.S. Provisional Application Ser. No. 61/263,304, filed Nov.20, 2009, and to U.S. Provisional Application Ser. No. 61/263,295, filedNov. 20, 2009, which applications and publication are incorporated byreference as if reproduced herein and made a part hereof in theirentirety, and the benefit of priority of each of which is claimedherein.

The present application is related to international application no.PCT/AU2007/000772, publication no. WO/2007/140514, entitled, “Vane Pumpfor Pumping Hydraulic Fluid,” filed Jun. 1, 2007; internationalapplication no. PCT/AU2006/000623, publication no. WO/2006/119574,entitled, “Improved Vane Pump,” filed May 12, 2006; and internationalapplication no. PCT/AU2004/00951, publication no. WO/2005/005782,entitled, “A Hydraulic Machine,” filed Jul. 15, 2004, the entirespecification of each of which is incorporated herein by reference intheir entirety.

TECHNICAL FIELD

This document relates generally to rotary couplings, and moreparticularly, to a hydrostatic torque converter.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate generally, by way of example, variousembodiments discussed in the present document. The drawings are forillustrative purposes only and may not be to scale.

FIG. 1A is a perspective view of a hydrostatic torque converter,according to some examples.

FIG. 1B is a cross section taken along line 1B-1B in FIG. 1A.

FIG. 2 is a cross section view of a hydrostatic torque converter,according to some examples.

FIG. 3A is a top view of a hydrostatic torque converter, according tosome embodiments.

FIG. 3B is a front view of the hydrostatic torque converter of FIG. 3A,according to some embodiments.

FIG. 3C is a cross section of the hydrostatic torque converter of FIG.3A taken along the line 3C-3C.

FIG. 3D is a cross section of the hydrostatic torque converter of FIG.3A taken along the line 3C-3C.

FIG. 3E is a cross section of the hydrostatic torque converter of FIG.3A taken along the line 3E-3E.

FIG. 3F is a partial cross section of the hydrostatic torque converterof FIG. 3A taken along the line 3F-3F.

FIG. 3G is a partial cross section of the hydrostatic torque converterof FIG. 3A taken along the line 3G-3G.

FIG. 4A is a cross section of the hydrostatic torque converter of FIG.3A taken along the line 4A-4A.

FIG. 4B is a cross section of the hydrostatic torque converter of FIG.3A taken along the line 4B-4B.

FIG. 5 is a partial cross section view of a balance piston of the coupleof FIG. 3A taken along the line 5-5.

FIG. 6 is perspective view of a portion of an input and output of thecouple of FIG. 2.

FIG. 7 is a schematic of a hydraulic couple including a cross-sectionview of a rotating group including pins to extend and retract vanes,according to some examples.

FIG. 8A is a perspective view of a hydraulic couple with a geared body,according to some examples.

FIG. 8B is a cross section taken along line 8B-8B in FIG. 8A.

FIG. 9 is a table showing experimental figures related to a firstoperating condition.

FIG. 10 is a table showing experimental figures related to a firstoperating condition.

FIG. 11 is a table showing experimental figures related to a firstoperating condition.

FIG. 12 illustrates a torque amplifier in a couple disengaged ofoperation, according to some embodiments.

FIG. 13 illustrates a torque amplifier in an driving mode of operation,according to some embodiments.

FIG. 14 illustrates a torque amplifier in a braking mode of operation,according to some embodiments.

FIG. 15 illustrates a torque amplifier in a regenerative braking mode ofoperation, according to some embodiments.

FIG. 16 illustrates a torque amplifier in a first mode of operation,according to some embodiments.

FIG. 17 illustrates a vehicle including a torque amplifier, according tosome examples.

FIG. 18 illustrates a load ultimately driven by an electrical motor,according to some embodiments.

FIG. 19A is a perspective view of a vane including a roller tip,according to an example.

FIG. 19B is a bottom view of FIG. 19A.

FIG. 19C is a top view of FIG. 19A.

FIG. 19D is a front view of FIG. 19A.

FIG. 19E is a side view of FIG. 19A.

FIG. 19F is a perspective view of FIG. 19B, cross-sectioned at line19F-19F.

FIG. 19G is a bottom view of FIG. 19F.

DETAILED DESCRIPTION

This describes examples in which a couple transmits rotary motion froman input of the couple to an output of the couple. In various examples,a couple is hydraulically controlled, such as with a pilot signal, tocontrol fixing a torque input of the couple and a torque output of thecouple such that a rotational torque on the input of the couple istransmitted to the output of the couple. In response to a further pilotsignal the couple is controlled to unfix the input of the couple and theoutput of the couple to allow the input of the couple and the output ofthe couple to rotate independently.

In various examples, a couple includes a hydraulic pump with a rotatinggroup coupled to an input of the couple, and with a rotating grouphousing coupled to an output of the couple. In various examples, byrotating the rotating group in the rotating group housing, the pump willpump oil once a threshold torque between the input of the couple and theoutput of the couple is reached. Until the threshold torque is reached,the pump transmits torque from the input of the couple to the output ofthe couple without pumping oil, and accordingly is highly efficient. Invarious examples, through pumping oil, a couple can be overloadedwithout damage. In some examples, the pumped oil escapes over a reliefvalve. In some examples, the maximum amount of torque transferred isadjustable by adjusting the relief valve.

The couple is useful in a variety of applications, such as to drive afan to cool a machine, to transmit torque in a vehicle, to controltorque transmission in an industrial machine, or to accomplish otheracts in which an output torque is to be selectively deactivated from aninput torque. The couple improves upon prior designs such as clutchesand torque converters by using a hydraulic device that can efficientlytransmit high torques. Some examples use vane pumps that can beeconomically manufactured.

The couple is efficient because there are few or no efficiency penaltieswhen the couple engages the input of the couple and the output of thecouple to spin together. When spinning together, there are few or nohydraulic efficiency losses such as those losses in a torque converterthat cannot lock. The couple further improves efficiency by enabling theselective disengagement of rotating machines. For example, aconventional power output of a machine, such as a power take-off, wouldnormally spin whatever was hooked to it in concert with the rotation ofthe power take-off. The couple improves upon this by enabling for thedisengagement of that which is coupled to the power output, savingenergy. In some embodiments, the couple uses a closed system requiringonly a pilot signal and an optional drain to tank or reservoir. Someexamples include an adjustable relief valve to control maximum torquetransmitted.

This document presents examples of a multi-mode torque multiplyingsystem. The system is to couple to a torque source such as an engine orelectric motor to output torque such as to a transmission or anotherpowertrain component. The pumps are controlled such as with a valve toselectively transmit power or absorb power for future use. The systemimproves upon prior drive designs by providing a hydraulicallycontrollable coupling between the torque source and a load to be drivenwith torque. Unlike other hybrid hydraulic approaches, in certaininstances the hydraulically controllable couple provides an improvedconfiguration in which the system can reduce or eliminate hydraulicpropulsion, and its associated inefficiencies, to improve performance ofa vehicle or industrial drive system.

FIG. 1A is a perspective view of a hydrostatic torque converter,according to some examples. FIG. 1B is a cross section taken along line1B-1B in FIG. 1A. Various embodiments include an input shaft 102 coupledto rotate a body 104 defining a chamber 105. The body 104, in someexamples, is a vane pump or vane motor housing or a portion thereof,such as a ring. In further examples, the body 104 is housing of anotherkind of pump, such as a piston pump or motor or a gear pump or motor.Rotating the body 104 can rotate the rotating group 105 and in turnrotate the output 103. Such rotating occurs in some examples when thecouple 100 is in mode in which the rotating group 105 works fluid suchas hydraulic fluid between the rotating group 105 and the body 104.

In the operational mode in which rotation of the body 104 works fluidbetween the body 104 and the rotating group 105, pressures between thetwo are maintained at a high level, resisting rotational movementbetween the two, thereby imparting high torque to the output 103. Torelease the rotating group 105 from a couple with the body 104 to allowindependent rotation of the input 102 and the output 103, the rotatinggroup 105 and the body 104 are switched to a mode in which the rotatinggroup 105 does not work fluid, thereby allowing the rotating group 105to rotate and thus the output 103 to rotate.

In various embodiments, the rotating group 105 is in fluid communicationwith an inlet 112. Some examples position portions of the couple 100 influid communication with an optional drain 114. A fluid signal from theinlet 112 is to switch the couple 100 from a first mode, in which theinput 102 can rotate with respect to the output 103, and a second mode,in which they are coupled due to the resistance of the rotating group105 to pump fluid by working fluid against the body 104. In variousembodiments, working surfaces 106 of the rotating group 105 are eitherdeployed in the first mode or retracted in the second mode. In adeployed mode, the working surface 106 works fluid to rotate the body104. In a retracted mode, the working surfaces 106 are retracted and dolittle or no work to fluid, thereby allowing the body 104 to move withrespect to the rotating group 105. Retainers 116 are used to eitherdeploy or retract the working surfaces 106. In some embodiments, thefirst mode deploys vanes of a vane pump, and in the second mode,retracts them.

Various examples include an optional remote pressure control 120. Insome examples, the remote pressure control is coupled to one side of abalance piston, with pump output in fluid communication with theopposite side of the balance piston. The balance piston is to controlwhether the pump can pump oil. For example, if the remote pressurecontrol is set to a pressure, the balance piston allows couplingdischarge pressure to rise until the coupling discharge pressure ishigher than the pressure, moving the balance piston to overcome theremote pressure control pressure. As the balance piston moves, itenables the coupling discharge to drain, such as to tank. In such amanner, the maximum torque transmitted is remotely controllable via theremote pressure control signal 120. In some examples, the remotepressure control is used in addition to a primary relief valve thatallows oil to pump in any case where a torque differential between acouple input 102 and a couple output 103 exceeds a predeterminedthreshold.

In some examples, the inlet 112, drain 114 and remote pressure control120 are coupled to a coupling housing 118, but the present subjectmatter is not so limited. In some of these examples, various seals areused to guide the inlet 112 signal to the appropriate portion of thecouple 100. Additional seals guide any excess fluid out the drain 114.Further seals guide the remote pressure control to a valve such as abalance piston. The drain 114 is optional and some examples controlwhich mode the couple 100 operates in without use of an drain 114. Insome examples, the housing 118 is omitted in favor of running theremaining portions of the couple 100 in an oil bath.

In additional embodiments, the inlet 112 is coupled to one of the input102 or the output 103. In some examples, the drain 114 is coupled to theother of the input 102 or the output 103. Some examples couple the inlet112 and the drain 114 both to one of the input 102 and the output 103.It should be noted that the assignment of the body 104 as the input isnot limiting, and the body could alternatively be coupled to an output.

The present subject matter includes embodiments in which workingsurfaces of other pumps are held in a retracted position. For example, aretainer retains a piston of a piston pump to prevent the piston frommoving in a cylinder bore to work a fluid.

FIG. 2 is a cross section view of a hydrostatic torque converter,according to some examples. In this embodiment, an input shaft 202 iscoupled to a rotating group 205 to turn the rotating group when thecouple 200 is in mode in which the rotating group 205 works fluid suchas hydraulic fluid between the rotating group 205 and the body 204.Various embodiments include an output shaft 202 coupled to rotate a body204 defining a chamber 205. The body 204, in some examples, is a vanepump or vane motor housing. In further examples, the body 204 is housingof another pump, such as a piston pump or motor or a gear pump or motor.

In an operational mode in which rotation of the rotating group 205 worksfluid between the body 204 and the rotating group 205, pressures betweenthe two are maintained at a high level, resisting rotational movementbetween the two, thereby imparting high torque to the output 203. Torelease the rotating group 205 from a couple with the body 204 to allowindependent rotation of the output 202 and the input 203, the rotatinggroup 205 and the body 204 are switched to a mode in which the rotatinggroup 205 does not work fluid, thereby allowing the rotating group 205to rotate and thus the input 203 to rotate.

In various embodiments, the rotating group 205 is in fluid communicationwith an inlet 212. A fluid signal from the inlet 212 is to switch thecouple 200 from a first mode, in which the output 202 can rotate withrespect to the input 203, and a second mode, in which they are coupleddue to the resistance of the rotating group 205 to pump fluid by workingfluid against the body 204. In various embodiments, working surfaces 206of the rotating group 205 are either deployed in the first mode orretracted in the second mode. In a deployed mode, the working surface206 works fluid to rotate the body 204. In a retracted mode, the workingsurfaces 206 are retracted and do little or no work to fluid, therebyallowing the body 204 to move with respect to the rotating group 205.Retainers 216 are used to either deploy or retract the working surfaces206. In some embodiments, the first mode deploys vanes of a vane pump,and in the second mode, retracts them. In some examples, inertial forcesdraw the working surface 206 out to meet the body 204, such as when theinput 202 is spinning rapidly.

Various examples include an optional remote pressure control 220. Insome examples, the remote pressure control is coupled to one side of abalance piston, with pump output in fluid communication with theopposite side of the balance piston. The balance piston is to controlwhether the pump can pump oil. For example, if the remote pressurecontrol is set to a pressure, the balance piston allows couplingdischarge pressure to rise until the coupling discharge pressure ishigher than the pressure, moving the balance piston to overcome theremote pressure control pressure. As the balance piston moves, itenables the coupling discharge to drain, such as to tank. In such amanner, the maximum torque transmitted is remotely controllable via theremote pressure control signal 220. In some examples, the remotepressure control is used in addition to a primary relief valve thatallows oil to pump in any case where a torque differential between acouple input 202 and a couple output 203 exceeds a predeterminedthreshold.

In some examples, the inlet 208 is coupled to a coupling housing 218,but the present subject matter is not so limited. In these embodiments,various seals are used to guide the inlet 212 signal to the appropriateportion of the couple 200. In some examples, the housing 218 is omittedin favor of running the remaining portions of the couple 200 in an oilbath. In additional embodiments, the inlet 112 is coupled to one of theoutput shaft 202 or the input shaft 203.

FIG. 3A is a top view of a hydrostatic torque converter, according tosome embodiments. FIG. 3B is a front view of the hydrostatic torqueconverter of FIG. 3A, according to some embodiments. FIG. 3C is a crosssection of the hydrostatic torque converter of FIG. 3A taken along theline 3C-3C. FIG. 3D is a cross section of the hydrostatic torqueconverter of FIG. 3A taken along the line 3C-3C. FIG. 3E is a crosssection of the hydrostatic torque converter of FIG. 3A taken along theline 3E-3E. FIG. 3F is a partial cross section of the hydrostatic torqueconverter of FIG. 3A taken along the line 3F-3F. FIG. 3G is a partialcross section of the hydrostatic torque converter of FIG. 3A taken alongthe line 3G-3G. This detailed depiction is of one embodiment, and otherembodiments are possible, including embodiments in which another styleof pump is used, such as a piston pump or a gear pump.

Various embodiments include an input 10 coupled to couple to a torquesource. An output 11 is to couple to a powertrain. Examples include abody 17 defining a chamber 302 in fluid communication with an inlet andan discharge pressure of the hydraulic couple 300. Various embodimentsinclude a rotating group that includes a rotor 9 to rotate around anaxis inside the chamber 302. In various embodiments, the rotor defines afirst slot 304 extending parallel to the axis along an exterior of therotor and opening to the chamber, and a second slot opposite the firstand opening to the chamber, the rotor further defining a retainerpassage in fluid communication with the first slot with a first vane 7disposed in the first slot and a second vane 7 disposed in the secondslot. Various embodiments include a hydraulically controlled retainerdisposed in the retainer passage to retain the first vane in a retractedvane mode of operation and to release the first vane in a vane extendedmode of operation in which the first vane and the second vane extend tomeet the body to hydraulically work fluid when the first vane and thesecond vane are moved with respect to the body. In various examples, apump motor output shaft 11 is propelled in the vane extended mode ofoperation.

Various embodiments include a coupling housing 1. Some examples includetwo end bodies 60 and a sleeve 62. Some sealed examples include rotaryseals 5 to retain the fluid. In various examples, the port 2 allows oilinto and out of the housing 1. In some examples, fluid is to flow to andfrom a separate reservoir. Alternatively, some examples use a largehousing that accommodates enough fluid for operation and cooling. Thecouple 300 is not limited to application in which the housing is used 1to retain fluid.

In some examples, port 4 is to engage and disengage the coupling 300 todrive by restraining and releasing the vanes 7. In some examples, port 4connects through passage P1 via bushing 8 into the rotor 9. In someexamples, this allows the vanes 7 to be either restrained or released,such as by moving retainers 71, including wide portions 70 and narrowportions 58, to move a ball 52 through a passage 54 at least partiallyinto a detent 50 to retain a vane 7. One example of vane retraction orrelease is set forth in US Patent Application Publication No.2006/0133946, commonly assigned and incorporated herein by reference.Release of the vanes will result in the operation of the coupling thatwill try to operate as a hydraulic pump.

In some examples, port 4 is to engage and disengage the coupling 300 todrive by restraining and releasing the vanes 7. In some examples, port 4connects through passage P1 via bushing 8 into the rotor 9. In someexamples, this allows the vanes 7 to be either restrained or released.One example of vane retraction or release is set forth in US PatentApplication Publication No. 2006/0133946, commonly assigned andincorporated herein by reference. Release of the vanes will result inthe operation of the coupling that will try to operate as a hydraulicpump.

In various embodiments, the drive shaft 10 is connected to the rotor 9.In some examples, the drive shaft 10 rotates inside bearings 12, 15 andbushing 8. The drive shaft is configured for connection to a powersource such as an electric motor or diesel engine or other in someembodiments. The output shaft 11 rotates inside bearings 13, 14 andbushing 16. Bearing applications can optionally be substituted withbushings, and vice versa. Shaft 11 is connected to a pump coupling ring17, in some embodiments. Some of these embodiments couple the shaft 11to wear plates 18. Further embodiments couple the shaft 11 to a thrustplate 19. In some examples, the thrust plate 19 retains the bearing 15.Some examples include a needle roller bearing 14 to add alignment andstability to the assembly. Some examples retain parts with fastenerssuch as screws into one assembly. In some examples, housing 20 and nut21 hold the assembly together to resist high pressure forces from oil inoperation urging the assembly apart.

In one mode of operation, the couple 300 releases vanes 7 on thespinning shaft resulting in the vanes 7 working a fluid to pump fluid.However, fluid escape from a pump chamber is resisted, such as byforcing the fluid against a relief valve calibrated to a predeterminedpressure such as a high pressure. It should be noted that since littlepumping occurs, part wear is less of a concern than in a vane pump. Insome examples, resistance to input energy is transmitted to an outputshaft 11. In some examples, the energy supplied is equal to, orsubstantially equal to in the case of some leakage, the pressure of theoil and the displacement of the ring. In this configuration,torque=pressure*displacement/2*Pi.

Port 3 in some examples provides remote control of a safety pressurerelief valve, such as one positioned in bore 6. Referring to FIG. 5,control of pressure in the couple 300 is effected by controlling thebalanced piston 21 situated in chamber 6. In various examples, thebalance piston 21 prevents uncontrolled free flow of fluid from one ormore pump chambers. In some examples, piston 21 is held by spring 22,but the present subject matter is not so limited.

In some examples, to resist the escape of the oil from the coupling,pressure is placed on both ends of piston 21 via port 24 and orifice 25.Such a configuration disposes a small force on the spring to retain thespool in place, closing off oil escaping from the chamber 6 to drain 23.In some examples, remote control of the pressure via passage P2 allowsadjustable pressure control or venting/unloading of the piston 21. Othercontrols are possible. In some examples, by the oil force pushing spool21 against spring 22, the system allows fluid to escape from port 24 todrain port 23. In some examples, port 23 is at a lower pressure toprovide suction. In some examples, the remote pressure control isadjustable up to 2000 pounds per square inch (13.8 MPa). In someexamples, the remote pressure control is provided via a 0.75 millimeterorifice.

In various examples, the input drive shaft 10 converts energy into ahydraulic force that is resisted by the forces on shaft 11. Thishydraulic force is generated from the fluid trapped by the vanes workingthe fluid against the rotor contained by the ring, pressure plates andthrust plates causing shaft 11 to rotate.

The present subject matter provides a compact couple. In some examples,a 100 horsepower coupling has a diameter nominally of 6 inches (15.2cm), which is smaller than a comparable plate of a clutch or lowpressure fluid coupling such as a torque converter. The present subjectmatter does not suffer from clutch burn out. At stall, the coupling isable to discharge over a safety pressure relief valve preventing“burn-out” or damage to machines coupled to one or both of the input andthe out. The present embodiments are efficient as the incorporateselected manufacturing tolerances that result in efficiencies higherthan conventional fluid couplings such as a torque converter thatrequire loose engineering tolerances for reliability.

FIG. 7 is a schematic of a hydraulic couple 700 including across-section view of a rotating group including pins to extend andretract vanes, according to some examples. A rotating group 705 includesworking surfaces 706 (e.g., the illustrated vanes) that are aided by afluid pressure assist signal 704 to extend away from the rotating groupto meet a body coupled to the output 703. The fluid pressure assist cansupply all of the force needed to extend the working surfaces 706, or aportion, with a remainder supplied by an inertial force experiencedduring high speed rotation of the input 702. In some examples, pin 708is coupled to or against an inner side of the working surface 706 tourge the working surface 706 against a body coupled to an output shaft703. In various embodiments, an inlet signal 712 is added to control theextraction or retraction of an retainer to lock one or more workingsurfaces 706 in a retracted position, or to unlock the retainers so thatthey can extend.

Some examples include a valve 714 to control pressurization of one ormore assist signals 704 to extend pins 708. In the illustrated mode, thevalve is adjusted to depressurize the assist signal 704, such as throughleakage or direction to a drain, such that the working surfaces are beretracted and locked with and inlet signal 712. In a second mode, thevalve 714 is adjusted to depressurize the inlet signal 712 such asthrough leakage or a drain, and to use an assist pressure source 716 topressurize an assist signal 704 to press fluid against a pin 708 to urgethe working surface 706 outward to meet a body coupled to output shaft703 thereby urging the working surface 706 to work a fluid disposedbetween the rotating group 705 and the body.

FIG. 8A is a perspective view of a hydraulic couple with a geared body,according to some examples. FIG. 8B is a cross section taken along line8B-8B in FIG. 8A. In various examples, rotation of an input 802 can bearrested by extending working surfaces 806 to work hydraulic fluidagainst a body 804 that has a surface 807, such as a geared surface, tooutput power via the surface 807. In the illustrated example, thesurface 807 includes gears that interface with another gear surface 809to rotate the gear surface 809 to turn the output 803.

The gear system 800 is useful in a number of applications. For example,in one application, the input 802 is fixed to an engine to rotate whilethe engine rotates. The output 803 is optionally coupled to asupercharger to rotate rotators of the supercharger. In variousexamples, providing a pilot signal to allow the working surfaces 806 towork a hydraulic fluid against the body 804 causes a hydraulicresistance between the two, resulting in rotation of the body 804 insynchrony with the surface 809 to turn the output 803. In this manner,the supercharger can be activated and deactivated with the provision ofa pilot signal. Devices such as a valve are used to switch to provideintake air while the supercharger is deactivated in various examples.

Accordingly, one benefit is that the gear system 800 can be activatedand deactivated. In moments when the gears are not used, such as inautomotive transmission embodiments in which only some gears are used atsome times, gear rotation can be substantially slowed or stopped, whichcan improve efficiency by reducing or eliminating windage lossesattributable to the rotation of the gear system 800 such as in an oilbath.

FIG. 9 is a table showing experimental figures related to a firstoperating condition. The table illustrates the power required to drive afan using a gear pump to gear motor topology, using a pressurecompensated piston pump to gear motor topology and using embodiments ofa coupling as disclosed herein. In some of these examples, an inputshaft is coupled to rotating member of a machine such as a crankshaft,and when a signal is provided, retainers release working surfaces suchas vanes so that they can work fluid to lock the couple to turn theoutput shaft to turn a fan blade. The gear pump/gear motor design showsthat at full speed, a large amount of power is used due in part toinefficiency. It should also be noted that the system has to be sized tooperate all the time, thereby wasting power when fan cooling is notneeded. In FIG. 10, the performance of the three topologies areillustrated at half fan speed. Such a condition is possible byregulating the pressure supplied to the couple so that the pressurecauses the couple to act as a motor or a pump, in essence rotating thefan attached to the output faster or slower than the rotation of input.The experimental results show that the coupling embodiment is nearly asefficient as the piston embodiment. In FIG. 11, the coupling embodimentis more efficient than the other topologies, due to the improvementsdiscussed herein.

The present subject matter benefits from precise control. In someembodiments, programmable torque settings effected by adjustment of thepressure relief setting result in a predetermined stall points. Such aprogrammable stall point can be either fixed or remotely by associatingthe relief valve setting with a remote conventional override reliefvalve. A further benefit is controlled acceleration or deceleration byvarying relief valve settings to match desired maximum torques. In suchembodiments, start and stop torques can be reduced to limit high peaktorque levels that can damage machinery.

FIG. 12 illustrates a torque amplifier in a couple disengaged ofoperation, according to some embodiments. Various embodiments include atorque source 1202. The torque source can be any source including, butnot limited to, engines such as diesel engines, and electric motors. Insome examples, the torque source is a variable speed torque source thatis intended to run at different speeds in operation. Examples includediesel engines used to move vehicles such as over the road trucks, offroad vehicles, and trains. In additional embodiments, the torque source1202 is intended to run at a constant speed in operation, such as anindustrial induction motor.

Various embodiments include a hydraulic couple 1204 to couple the torquesource 1202 to powertrain 1206. One example of a hydraulic couple isillustrated in FIGS. 25-27, but the present subject matter is not solimited and extends to other hydraulic couples disclosed herein. Asdisclosed herein, the hydraulic couple 1204 includes retainers to retainworking surfaces that would, in an unretained mode, work 1205 hydraulicfluid through the couple. In various examples, a pilot signal 1203 isused to control the retainers. The system 1200 includes hydraulic pumpmotor 1208 such as a digitally controlled piston pump. The pump motor1208 can be controlled by various methods including, but not limited to,electronically, pressure compensated, lever, or digitally. The pump 1208includes an output shaft 1210 coupled to the powertrain 1206, thehydraulic pump including a pump motor inlet 1212 in fluid communicationwith the discharge pressure 1214 of the hydraulic couple 1204, the pumpmotor 1208 to receive fluid 1216 from the discharge pressure 1214 of thehydraulic couple 1204 to propel the output shaft 1210.

Various examples include a valve 1218 to control operation of the system1200. An optional accumulator 1220 can store pressurized fluid. Anoptional shuttle valve 1222 ensures one-way flow of the fluid 1216 insome examples. Some examples include a reservoir to store fluid. A drain1226 optionally returns to the reservoir 1224 or to another fluidstorage device.

In various examples, the powertrain 1206 includes a transmission 1228.There are several benefits of the system 1200 as it relates totransmissions. In FIG. 12, the couple 1204 is configured to allow theinput 1202 to spin with respect to the output shaft 1207. This isequivalent to a neutral condition for the vehicle. The pump 1208 can bestroked on slightly or fully in this condition; the degree of stroke isinconsequential as there is little inlet pressure.

FIG. 13 illustrates a torque amplifier in a driving mode of operation,according to some embodiments. The illustrated mode of operationcorrelates to a steady state driving condition. Torque to the inputshaft 1202 is transmitted to the output shaft 1207 with few or nolosses; the couple 1204 effectively works as a mechanical shaft. Therelief valve 1230 allows the couple 1204 to slip should a problem occur,in a manner that a clutch might slip. In additional embodiments, therelief valve 1230 is used to control the torque output magnitude of thecouple 1204.

In arriving at the state illustrated in FIG. 13, a number of beneficialoperations occur. In some examples, before a first gear is selected, atorque source 1202 such as an engine is spinning such as at 1500 rpm. Asthe first gear is selected, such as via positioning the transmission1228 into a first gear, the hydraulic couple releases working surfacessuch as vanes so that the hydraulic couple 1204 pumps against a fluid1216. Provided the valve 1218 is so adjusted, the hydraulic couple 1204begins to pump fluid 1216 to the pump 1208. The pump receives fluid 1208and strokes on gradually to begin to move the powertrain 1228. After asteady state is reached, if a boost of torque is required, the systemcan again introduce hydraulic motor torque through 1210 on top of thetorque the engine produces through 1207.

In some examples, after a steady state driving mode is reached, thevalve 1218 selects to resist pumping by the couple 1204. The couple 1204essentially locks except for any leakage, and the pump 1208 strokes off.In this mode, the input 1202 is locked to the output 1207 and thereby tothe transmission 1228 and the inefficiencies of the hydraulic system aresubstantially reduced or eliminated. Further, the risk of damaging themotor pump 1208 is reduced.

Accordingly, several benefits are realized including reducing peaktransient forces experienced by the transmission 1228. The peaktransient forces are reduced by the couple 1204 separating the enginefrom the transmission 1228 and the pump 1208 gradually adding them backto the transmission 1228. Because of the adjustability of the system,the vehicle can operate with a simpler transmission that includes fewerspeeds. Such transmissions are less expensive, are easier to repair, arelighter, and because they have less complexity, are less likely tobreak.

FIG. 14 illustrates a torque amplifier in a regenerative braking mode ofoperation, according to some embodiments. In this embodiment, the couplecan be engaged or disengaged. The pump motor 1208 is stroked to apumping mode to direct fluid generated during vehicle deceleration intothe accumulator 1220. If the accumulator is full, the pump can be usedto force fluid over a relief valve, or it can optionally be stroked offof pumping. In various examples, wheel brakes are used to assist instop. In some additional examples, the couple 1204 is engaged to allowfor engine braking.

FIG. 15 illustrates a torque amplifier in a regenerative braking mode ofoperation, according to some embodiments. In this example, energy storedin the accumulator 1220, such as energy stored during deceleration ofthe vehicle, is used to accelerate the vehicle. The valve 1218 isadjusted and the pump motor is stroked to a motor mode to propel thevehicle. In this mode, the coupling 1204 is engaged and pumps fluiduntil the resistance from the fluid 1216 reaches a magnitude tosubstantially lock the couple 1204. The fluid 1216 can reach such apressure through adjustment of the valve 1218. The fluid 1216 canadditionally reach such a pressure when the pump motor 1208 experiencesa high resistance to propulsion.

FIG. 16 illustrates a torque amplifier in a first mode of operation,according to some embodiments. This embodiment illustrates an optionalgear set 1250 to alter the rotation ratio between the torque source 1202and the transmission 1228 so that it's a ratio other than 1:1.

FIG. 17 illustrates a vehicle including a torque amplifier, according tosome examples. The illustration represents one possible configuration,and others are possible. By positioning the hydraulic couple 1204 beforethe transmission, more operational modes are possible than withconfigurations in which a hydraulic pump or pump motor is downstream1240, such as when the pump motor is between the transmission 1228 and adifferential for an axle.

One benefit of the system 1200 is that the fluid 1216 can optionally beused to drive accessories such as dump boxes. This is an improvementover designs in which a pump 1208 is between a transmission and theremainder of the powertrain because in those systems, the vehicle wouldhave to be moving in order to provide pumped fluid to drive anaccessory. In the present examples, a valve can allow the couple to pumpfluid to drive an accessory. Another benefit of the system 1200 is thatin a steady state driving mode the system does not emit hydraulic noise,sparing the operator from listening to what is often regarded as anunpleasant noise.

FIG. 18 illustrates a load ultimately driven by an electrical motor,according to some embodiments. The system 1800 includes grid power 1802that is used to power an motor 1804 such as an AC induction motor. Themotor 1804 is coupled to the hydraulic couple 1806 to provide an inputtorque. As discussed herein, the hydraulic couple 1806 is to cooperatewith the pump 1808 to gradually introduce torque to the powertrain 1810,thereby working the load 1812. Such a configuration reduces thecomplexity of the system 1800 when compared to designs using a gearboxor a larger, more expensive multi-speed motor.

FIG. 19A is a perspective view of a vane including a roller tip,according to an example. FIG. 19B is a bottom view of FIG. 19A. FIG. 19Cis a top view of FIG. 19A. FIG. 19D is a front view of FIG. 19A. FIG.19E is a side view of FIG. 19A. FIG. 19F is a perspective view of FIG.19B, cross-sectioned at line 19F-19F. FIG. 19G is a bottom view of FIG.19F. A vane 1902 includes a journal 1903 in which a vane 1904 isdisposed. In some optional configurations, a port 1906 extends from thebottom of the vane to the journal 1903 to provide hydraulic fluid to thevane, such as to lubricate it, to balance it in a vane pump and/or toprovide a hydrodynamic bearing to support the vane 1904.

The present detailed description refers to subject matter in theaccompanying drawings that show, by way of illustration, specificaspects and embodiments in which the present subject matter may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the present subject matter.References to “an”, “one”, or “various” embodiments in this disclosureare not necessarily to the same embodiment, and such referencescontemplate more than one embodiment. The present detailed descriptionis, therefore, not to be taken in a limiting sense, and the scope isdefined only by the appended claims, along with the full scope of legalequivalents to which such claims are entitled.

This application is intended to cover adaptations or variations of thepresent subject matter. It is to be understood that the abovedescription is intended to be illustrative, and not restrictive. Thescope of the present subject matter should be determined with referenceto the appended claims, along with the full scope of legal equivalentsto which such claims are entitled.

1. (canceled)
 2. A system for a vehicle, the system comprising: ahydraulic coupling comprising: a rotor disposed for rotation about anaxis; a plurality of vanes each moveable relative to the rotor between aretracted position and an extended position where the plurality of vaneswork a hydraulic fluid introduced adjacent the rotor, wherein each ofthe plurality of vanes has an outer tip with a recess therein; a rollermounted at the outer tip of each of the plurality of vanes at leastpartially positioned within the recess; and a ring disposed at leastpartially around the rotor; an input shaft and an output shaft coupledto rotate together by the hydraulic coupling in the vane extended modeof operation, and the input shaft and output shaft are free to rotatewith respect to one another in the vane retracted mode of operation; andan accumulator configured to store pressurized fluid.
 3. The system ofclaim 2, wherein the hydraulic coupling is configured to retain the oneor more of the plurality of vanes in the retracted position within therotor and is configured to release the one or more of the plurality ofvanes from the rotor to the extended position.
 4. The system of claim 2,further comprising a hydraulic pump motor coupled to the output shaft,the hydraulic pump motor including a pump motor port in fluidcommunication with the hydraulic coupling configured to selectivelydeliver an amount of fluid at a discharge pressure, the pump motorreceives fluid from the hydraulic coupling to propel the output shaft inthe vane extended mode of operation.
 5. The system of claim 4, whereinthe hydraulic pump motor comprises a digitally controlled piston pump.6. The system of claim 4, wherein the pump motor is configured tooperate to pump pressurized fluid generated during vehicle decelerationto the accumulator in a regenerative braking mode of operation for thevehicle.
 7. The system of claim 4, wherein the pressurized fluid storedin the accumulator is used by the pump motor to accelerate the vehicle.8. The system of claim 4, wherein the pump motor is configured to bestroked at least one of slightly or fully when the vehicle is in aneutral condition.
 9. The system of claim 4, further comprising: atorque producer coupled to the input shaft; and a powertrain coupled tothe output shaft, wherein the hydraulic motor pump strokes on graduallyto move the powertrain in a drive mode of operation for the vehicle. 10.The system of claim 2, further comprising a relief valve that controls atorque output magnitude of the coupling.
 11. The system of claim 2,wherein the coupling is configured to act as a mechanical shaft to lockthe input shaft to the output shaft and the pump motor strokes off whenthe vehicle is in a steady state driving mode of operation
 12. Thesystem of claim 2, wherein the motor pump is configured to boost torqueon the output shaft.
 13. A method comprising: providing a hydraulicdevice configured as both a coupling and a vane pump, wherein thehydraulic device has a plurality of vanes that are extendable from andretractable in a rotor, and wherein a tip of each of the plurality ofvanes includes a roller bearing; and flowing a pressurized hydraulicfluid from the hydraulic device to an accumulator.
 14. The method ofclaim 13, further comprising selectively coupling a pump motorselectively with the hydraulic device.
 15. The method of claim 14,flowing the pressurized hydraulic fluid from the hydraulic device to thepump motor.
 16. The method of claim 14, comprising bleeding pressuregenerated by the vane pump over a relief valve when the accumulator isfull.
 17. The method of claim 14, comprising driving, after theregenerative braking mode, the load with the vane pump using hydraulicpressure stored in the accumulator.
 18. The method of claim 13,comprising storing the pressurized hydraulic fluid in the accumulator ina regenerative braking mode.
 19. A vehicle system comprising: ahydraulic coupling having a body and at least a first vane configuredfor movement relative to the body, the hydraulic coupling adapted toretain the first vane in a retracted vane mode of operation and torelease the first vane in a vane extended mode of operation in which thefirst vane extends to meet the body to hydraulically work fluid when thefirst vane is moved with respect to the body; an input shaft and anoutput shaft coupled to rotate together by the hydraulic coupling in thevane extended mode of operation, and the input shaft and output shaftare free to rotate with respect to one another in the vane retractedmode of operation; an accessory configured to operate as a pump in oneoperation mode to pump a pressurized fluid; a torque producer coupled tothe input shaft; and an accumulator configured to store pressurizedfluid.
 20. The system of claim 19, further comprising a transmissioncoupled to the output shaft, wherein the coupling is disposed betweenthe torque producer and the transmission and is in fluid communicationwith and drives the accessory in the vane extended mode of operation.21. The system of claim 19, wherein the accessory comprises a motorpump.